Telephone-transmitter.



L- B. STONE v TELEPHONE TRANSMITTER. APPLICATION FILED APR. 4, 1914. RENEWED AUG. 11, 1911.

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L. B. STONE.

. TELEPHONE TRANSMITTER. APPLICATION man MBA-T1914- RENEWED AUG. I7, 1911.

Patented Apr. 16, 1918.

2 SHEETS-SHEET 2- LONNIE BURNETT STONE, 'OF LOUISVILLE, KENTUCKY. V

TELEPHONE-TRANSMITTER.

7 Specification of Letters latent.

Application filed April 4:, 1914, Serial No. 829,610. Renewed August 17, 1917. Serial No. 186,824.

To all whom it may concern:

Be it known that I, LoNNni BURNETT STONE, a citizen of the U. S. of America, residing at Louisville, in the county of J efierson and State of Kentucky, have invented new and useful Improvements in Telephone- Transmitters, of which the following is a specification.

This invention relates to improvements in telephone transmitters and has particular application to a transmitter employlng a plurality of microphonic units.

In carrying out the present invention, it is my purpose to provide a transmitter of the class described wherein by means of a number of microphonic units connected in multiple in an electric circuit and an induction coil having the primary thereof clivided into independent sections connected in multiple in the circuit and corresponding in number with the microphonic units and the secondary winding thereof divided into sections corresponding with the number of sections in the primary winding and connected in series in the line, the action of the different or segregated primaries will simultaneously induce currents in the secondary winding to produce a working current equal to the sum of the potentials of the separately induced currents, thereby reducing the internal resistance and enabling the sound waves issued from the receiver connected in circuit with such transmitter to be am- It is also my purpose to provide a, transmitter of the type set forth which will embrace the desired features of-simplicity, efficiency and durability, which may be manufactured, marketed and installed at a minimum expense and whereby the sound waves will be distinctly and clearly transmitted.

With the above and other objects in view, the invention consists in the construction, combination and arrangement of parts hereinafter set forth in and falling withinthe scope of the claim.

In the accompanying drawings Figure 1 is a vertical sectional view through a transmitter constructed in accordance with the present invention, parts being shown in elevation.

through, parts being shownin elevation.

Fig. 3 is a view in side elevation of one of the microphones, parts being broken away. Fig. 4 is a diagrammatic iew showing the circuit connections.

Patented A t. is, rare.

' Fig. 2 is a transverse sectional View there-2 F ig. 5 is a transverse sectional :view

through the microphone shown in Fig. 3.

Fig. 6 is an end view of the microphone.

. Fig. 7 is a fragmentary sectional view through the transmitter showing one of the dampening springs. for the sound diaphragm.

Fig. 8 is a detail view.

Referring now to the accompanying drawings in detail, 1 designates a receptacle or retainer constructed of any suitable material and of any desired outline and having the rear end thereof equipped with an outwardly extending pivot .post 2 pivotally connected with the upper end of the usual standard mounted upon the base. The front end ofthe container or receptacle 1 is open and secured thereto in some suitable manner and closing the same is a cover plate 5 equipped centrally with an opening 6 and threaded into the opening 6 and extending outwardly from the cover plate 5 is a mouth piece 7.

Seated within the receptacle 1 at the open.

end thereof and preferably insulated from the receptacle is an annulus 8 and bolted or otherwise connected to the annulus 8 at diametrically opposite points are feet 9, 9 extending outwardly from the extremities of the parallel limbs 10, 10of a substantially U-shaped yoke 11, the interconnecting memher of such yoke being disposed in a plane parallel with that of the annulus and eX-.

phone comprises, a cylindrical shell 1 L form- 1 inga chamber containing carbon granules 15 or the like and lined with suitable'insulating material. In this instance, the shells constituting the carbon chambers are arranged srde by side in triangular formation and are formed integral with a block 16 of insulating material, an end view of which is shown in Fig. 8, disposed between such shells and holding the same in proper relative positions. The rear ends of these shells are closed by means of metallic caps 17 carrying carbon blocks 17 disposed within the rear ends of the carbon chambers and in contact with the carbon granules within the chambers, while the forward ends of the shells are closed by means of mica disks 18 lying against the end edges of the shells and secured to the latter through the medium of rings 19 abutting the edges of the shells and secured thereto through the medium of screw studs. Fastened to each mica disk 18 centrally thereof and having the inner face thereof in contact with the carbon granules within the adjacent chamber is an electrode 20 composed. of any suitable material and connected with the electrodes 20 of the carbon chambers are the limbs of a spider 21 having the central portion thereof disposed approximately centrally of the adjacent end of the block 16 and equipped with an outstanding pin 22. Connected with the rear end of the block 16 and projecting outwardly therefrom is a pin 23 electrically connected with the caps 17 on the adjacent extremities of the shells 1 1 and passed through a collar 2 1 secured to the central portion of the interconnecting member of the yoke 11. This collar 2% is provided with a set screw 25 adapted to bind against the pin 23 to support the microphonic units within the casing or receptacle 1 of the transmitter. Owing to the interconnecting member of the yoke 11 being disposed at the rear of the annulus 8 and in a plane parallel therewith, the forward extremities of the shells 1 1 constituting the carbon chambers will be disposed in approximately the same plane as the annulus 8. Fastened to the front edge of the annulus is a diaphragm 26 capable of vibrating under the action of sound waves and having the central portion thereof connected with the pin 22 on the spider so that as the diaphragm vibrates under the action of the sound waves the electrodes 20 will respond to such vibrations with the effect to vary the resistance in the circuit in which the transmitter is connected.

In the present embodiment of my inven- In practice, the binding posts 33 and 3 1 are connected with the terminals of an electric circuit 35 including a suitable source of electrical energy as a battery 36 .and con- 7 nected in multiple with the circuit 35 are the primary windings P of independent i11- duction coils 37 while the secondary windings S of the induction coils are connected in series in the line 38, as clearly illustrated in the diagrammatic view.

From the foregoing description taken in connection with the accompanying drawings, the construction and mode of operation of my improved telephone transmitter will be readily apparent. When the circuit 35 is closed current flows from one side of the battery 36, through the wire 32 by way of the binding posts 33 and31 and the plate 30, the pin 22, the arms of the spider 21, the carbon granules in the individual chambers, the pin 23 electrically connected with the rear walls of such chambers, the interconnecting member of the yoke 11, binding post 3 1, the primary windings of the induction coils and then back to the other side of the battery. Upon the energization of the primary windings of the induction coils 37 current is induced in the secondary windings and fed to the line 38 as is well known. When the diaphragm 26 is set in motion under the action of the sound waves the electrodes 2O vibrate within the carbon chambers and so vary the resistance in the talking circuit whereby the sound waves are reproduced at the receiving end of the circuit as is well understood.

It will be seen that I have provided a multi-microphonic transmitter wherein the internal resistance is reduced to a minimum and current induced in the secondary windings of the induction coils from the primary windings of such coils, such current being equal to the sum of the potentials of the separately induced currents.

While I have herein shown and described one preferred form of my invention by way of illustration, I wish it to be understood that I do not limit or confine myself to the precise details of construction herein described and delineated, as modification and variation may be made within the scope of the claim without departing from the spirit of the invention.

I claim:

In a device as described, in combination a pivotal arm, a bell-shaped receiver on said arm, a yoke arranged in said bell and consisting of a channel-shaped member having its back seated against the inner circumference of said bell, a plurality of granule containing spools horizontally supported upon the back of said yoke, and a pressure transmitting button, radial arms extending from said pressure, transmitting button and engaging said granules in said spools, an annular member, flanges carried by said yoke,

being secured upon said annular member,.

said diaphragm, a cap removably engaging said bell, and holding said diaphragm Gop'ies of this patent may be obtained for against displacement and a speaking tube carried by said cap.

In testimony whereof I afiiX my signature in presence of two Witnesses.

LONNIE BURNETT STONE.

l/Vitnesses:

LOIS N. 'BAREroo'r, MAPPEsE. POWERS.

five cents each, by addressing the "Commissioner of Eatente,

Washiv qton, D. 0. 

